Powder metallurgy



Jam 15, 1946. H, A, TQULMlN7 JR 2,393,130

POWDER METALLURGY Filed July l2. 1944 6 Sheets-Sheet l ma @im INVENTOR HARRY Mmmm JR. BY

ATTORN EYS Jan. l5, 1946. H. A. TouLMlN, JR

POWDER METALLURGY 6 Sheds-Sheet 5 Filed July 12, 1944 m Q j .MHMH

ATTORNEYS 6 Sheets-Sheet 4 POWDER METALLURGY H. A. TouLMlN, JR

Filed July 12, 1944 EMI? INVENTOR HARRY A.TOULM|N JR.

m o fw' Jan, 15, 1946.

POWDER METALLURGY Filed July l2, 1944 6 Sheets-Sheet 5 INVENTOR HARRY ATouumN JR. BY

u a ATI' RNEYS Jan. l5, 1946. H A TOULMlN, JR 2,393,130

POWDER METALLURGY Filed July 12, 1944 es sheets-sheet 6 esssssosssoo, IIIIIII/ Emi QSHLLATIMI lll/lll lll INVENTOR 2115 242 Blinnm ATouLmN JR.

2x ATTORNEYS quality.

Patented Jan. 15, 1946 POWDER METALLURGY Harry A. Toulmin, Jr., Oakwood, Ohio, assignor to H-P-M Development-Corporation, Wilmington, Del., a corporation Delaware Application July 12, 1944, Serial No. 544,565

13 Claims.

This invention relates to powder metallurgy and, more particularly, deals with a method and apparatus for compacting metal powders.

In the art of forming workpieces of metal powders it is of importance that the quality of the workpiece be uniform throughout. This requires that the compacted powders be alloyed or sintered uni-formly throughout the completed workpiece in order to avoid porous. low strength areas. inasmuch as the compacted workpiece is formed of discreet particles prior to the sintering operation, the conduction of heat therethrough is inhibited by the voids between the said particles. The consequence of attempting to sinter or alloy a workpiece compacted of powdered metals by heating the same from the surface inwardly leads to non-uniformity and density, electrical properties and mechanical quality.

Accordingly, the primary object of the present invention is to provide a method and apparatus particularly adapted to overcome the aforementioned diiiiculties and to produce compacted metal powdered articles characterized by uniformity of structure, electrical properties and mechanical This and other objects will become apparent upon reference to the following description taken in connection with the following drawings, in which:

Figure 1 is an elevational view of a press adapted for the practice of this invention;

Figure 2 is an enlarged fragmentary view, partly in cross section, of the press shown in Figure 1;

Figure 3 is a fragmentary view similar to Figure 2 but showing the press parts during a different stage of the pressing process;

Figure 4 is a sectional view through a modification of the apparatus of this invention;

Figure 5 is similar Yto Figure 4. but showing an apparatus after the workpiece has been compacted therein;

of stili another modiiied structure arranged according to this invention;

Figure 11 is an enlarged sectional view of a portion of the structure shown in Figure l0;

Figure 12 is a; fragmentary view of the preheating cylinder of Figure 10 illustrating a modi- .ed' arrangement of the heating apparatus therefor;

Figure 1.3 is a diagrammatic elevational view of another modified press arrangement constructed according to this invention;

Figure 14 is an enlarged sectional view of a portion of Figure 13;

Figure 15 is a diagrammatic view, partly in section, of another modified press structure including an automatic weighing device and constructed according to this invention;

Figure 16 is an enlarged sectional view of a portion of Figure 15 showing the press parts in a different stage of the operating cycle; and

Figure 17 is a sectional view showing a modied form of preheating chamber.

General arrangement In general, this invention comprises a first chamber adapted to receive a measured charge of metal powder and having associated therewith Figure 6 is a view similar to Figure 4 but shows V the workpiece being ejected from the compacting cylinder Figure 7 is a view, partly in section, of the apparatus of Figure 4 showing more fully the `construction thereof;

Q, Figure 8 is a diagrammatic elevational view means for preheating the metal to somewhat below sintering or alloying temperature. Optionally, the metal powder may be preheated before placing the same in the said chamber.

The preheated metal having been placed in the rst chamber, or the metal powder having been heated therein, the same is transferred to a compacting chamber where it is pressed by a pressing plunger into a compact mass. The compacting chamber may include means for heating the metal therein so as to sinter or alloy the same into a completed workpiece, but it is likewise conceivable that the workpiece may be further sintered in an oven subsequent to the final compacting and heating step.

The charge of powder which is to be compacted inte a workpiece may be measured by volume or weight, either method producing satisfactory resuits.

The means for heating the metal in the preheating stage or in the compacting chamber or subsequent to the compacting step is, preferably, accomplished by means of high frequency electromagnetic induction. This method of heating permits the workpiece to be heated uniformly throughout its mass so as to produce a workpiece uniform as to density and other necsary qualities.

Structural arrangement of the embodiment of Figure 1 Referring to Figure l, the press structure shown therein comprises a xed bed or platen I which is connected by the strain rods 35 and 3S to the stationary cross head II. Reciprocably mounted on the strain rods 35 and 36 is a movable platen I2 which carries a cylinder 26. The cylinder 20 is adapted to be moved into engagement with the cylinder 32, carried -by the iixed platen I0, as shown in Figure 3.

'I'he cylinder 20, which is a measuring and prehating cylinder, is surrounded by an induction coil 22 adapted to receive electrical energy for preheating a charge of powdered metal 2| within the cylinder 20. A sleeve V23 of insulating material surrounds the coil 22 so as properly thermally and electrically to insulate the said coil and the cylinder 26.

'I'he platen I2 is supported by a spring 216 which bears against the collar 25 fixed to the plunger 24, the said plunger being reciprocable within the cylinder 20. The plunger 24 is attached to a motor means, preferably hydraulic, indicated at 28 which is supplied with actuating iiuid through a f our-way valve at 29. The hydraulic motor 28 is adapted to move the platen I2 and the cylinder 26 upwardly into the position shown in Figure 3, while the spring 2S is effective thereafter to permit the plunger 24 -to move upwardly through the cylinder 20 to transfer a charge of powdered metal 2| into the compacting cylinder as shown in Figure 3.

The compacting cylinder, indicated at 32, is carried by the fixed platen I0 and has reciprocably mounted therein the plunger 3|. The plunger 3| forms a bottom against which the powder 2| is compacted and also serves as an ejector plunger following the compacting and sintering of the powder within the cylinder. .The plunger 3| may be actuated by a hydraulic motor which is supplied with actuating fluid through a four-way valve 36.

The compacting cylinder 32 is surrounded by an induction coil 33, similar to the coil 22-in Figure 2, and an insulating sleeve 34 surrounds the said coil and cylinder.

The coils 22 and 33 are connected by the/wires I3 and I4 with an oscillation generator generally indicated at I5. The generator I5 may be of any type capable of producing alternating current of lthe desired frequency and voltage for inducing in the powdered metal suilicient magnetic and electric losses to produce the desired heating effect.

As seen in Figure 2, the plunger 24 is urged downwardly relative to the cylinder 20 by the spring 26 until the shims21 engage the underside of the enlarged end portion of the plunger 24. It will be apparent that the capacity of the cylinder 20 may be varied by varying the number or thickness of the shims 21 so as to vary -the amount of powdered metal which may be contained within the said cylinder.

Operation of the embodiment of Figure 1 In operation the parts of the press shown in Figure l are initially positioned as indicated in Figure 2.. The cylinder 20 is then lled with powdered metal, the exact quantity depending on the arrangement of shims at 21. The induction coil 22 is then energized by closing the switch I6 in the wire I3 thereby completing the circuit to the oscillation generator I6. After a predetermined length of time the switch I6 may be opened and the valve 29 shifted to actuate the motor 28 to move the platen I2 and cylinder 2I'I upwardly into their Figure 3 position. After the cylinder 20 engages the lower end of the cylinder 32 the spring 26 is effective to permit the plungerl 24 to continue to advance to transfer the charge of preheated powdered metal into the compacting cylinder 32. The metal powder is compacted within the cylinder 32 :between the plungers 24 and 3|. Prior to, during or subsequent .to the compacting of the powder, the switch I1 may be closed to energize the coil 33. Suilicient power is delivered to the coil 33 and, therefore, to the powder 2| to bring the same to sintering or alloying temperature.

When the workpiece has been completely compacted and sintered, the cylinder 2B and plunger 24 are returned to their Figure 2 position and the valve 30 is shifted to actuate the hydraulic motor associated-with the plunger 3| to cause the work-piece to be ejected from the compacting cylinder. The plunger 3| is then returned to its upper position and a new cycle of operations may be commenced.

It will Ibe apparent that the plungers 24 and 3| may, if desired, -be withdrawn from the cylinder 32 during the sintering operation in order not to detract. from the heating elect of the iield of electromagnetic induction set up by the coil 33.

Structural arrangement of the embodiment of Figure 7 'Referring now to Figures 4 to 7 inclusive, a somewhat modified arrangement of a press according to this invention is shown. In this modication the measuring and compacting cylinders are arranged horizontally and the powdered material is fed into the former from a hopper through a passage wherein the metal may be preheated.

The general arrangement, without the hopper, is shown in Figure '7. In this figure, the measuring cylinder or chamber indicated at 54 is slidably mounted on the rods 6I and 62. The rods 6I and -62 are joined at one end by the cross head 63 rigidly attached thereto and at the other end by the cross heads 64 and 65, slidable thereon. The springs 66 and 61 mounted, respectively, on the rods 6I and 62, bear between the cross head 63 and the chamber 54, urging the latter rightwardly into engagement with the compacting cylinder 56.

The compacting cylinder 56 is stationary and has reciprocably mounted therein the plunger 51 which is rigidly attached to the cross head 65. The compacting cylinder -56 has associated therewith the induction coil 58 and insulating sleeve 59 arranged in a manner similar to that of the coil 22 and sleeve 23 of Figure 2.

Reciprocably mounted 'within the chamber y54 is a plunger which is pinned to the cross head 63 as at 60 and to which is attached the hydraulic motor 14. The actuation of the motor 14 and, therefore, the cross head 63 and the plunger 55 is controlled by the four-way valve 15.

For a purpose which will become apparent hereinafter, the cross head 63 carries a latch member 10 which is adapted to engage a cooperating portion 'II on the chamber 54. The latch member 10 is pivotally mounted on the cross head 63 andis adapted to engage the portion 1I when the plunger 55 is in its extreme right hand position to be disengaged therefrom when the plunger is in its`extreme left hand position by the cam 12.,

The cross head 54 is engaged by the springs 88 and 88 which urge the same leftwardly to be engaged by shoulders on the rods BI and 52. The purpose of this arrangement is to permit the plunger l in the cylinder 58 to halt when bottomed on the end of the said cylinder while permitting the plunger 55 and the rods 62 and 8| to continue their rightward movement to compact the metalwithin the compacting cylinder.

Referring to Figure 4, the hopper 50 is shown to be connected with the chamber 54 andto have arranged therearound the induction coil 52 and the insulating sleeve 53. The powdered metal Within the hopper 68 is heated within the zone 5i as it isV fed into the chamber 55.

Operation of the embodiment of Figure 7 Referring to Figures 4 and 7, the plungers 55 and 51 are shown disposed within the chamber 54 to receive a charge of powdered metal therebetween. The powder has been preheated in passing through the zone 5i and is, therefore, at a temperature preferably somewhat below the sintering temperature of the material.

The charge is transferred to the compacting chamber by the actuation of the valve 'i5 which actuates the motor 'it to move the plunger 55 and the cross head S3 to the right into the position shown in Figure 5. As the plunger and cross head move to the right, the rods El and 52 likewise move to the right and, through the cross head 88 and the springs 58 and 89, urge the cross head 55 and the plunger 51 attached thereto to the right also. When the plunger 51 bottoms against the right hand end of the cylinder 56 the springs 88 and 59 permit the rods 5i and 62. cross heads 5t and 65 and the plunger 55 to continue the rightward movement. The continued rightward movement of the plunger 55 is effective to compact thepowdered metal within the chamber 55 as is indicated in Figure 5. During this time the compacted powder is heatedy by electromagnetic induction from the coil 58 which has been energized.

As the plunger approaches its Figure 5 position the latch member 'i8 engages the member 1| on the chamber 5t as seen in Figure 5. Following the complete sintering of the workpiece, or as much of the sintering cycle as it is desired to accomplish within the chamber 55, the valve 75 is shifted so as to actuate the motor M to retract the plunger 55 from the compacting chamber.

As the plunger 55 retracts it carries with it the chamber 55 because of the engagement of the latch 'l0 with the member 1l. Also, after plunger 55 has retracted a predetermined amount the rods 5I and 62 which are moving with the plunger 55 are effective to engage the cross head 65 and forcibly to eject the completed workpiece or briquette from the chamber 56. This stage of the cycle is indicated at Figure 6 where the chamber 55 is retracted from the chamber 56 and the plunger 51 is ejecting the briquette from the machine.

A further retracting movement of the plunger 55 from the position indicated in Figure 6 brings the cam 12 into engagement with the latch memberili, rotating the latter counterclockwise and releasing the member 1l from engagement therewith. The springs 66 and 61 are then effective to move the chamber 55 toits Figure 7 position in engagement with the chamber 56. The springs 58 and 81. areof such a size that the movement asaaiso of the chamber from its Figure 6 position to its Figure 7 position is accomplished with suillclent speed that the powder within the hopper does not have an opportunity to pour from the open end of the chamber 54. Rather, the sudden movement of the chamber 54 into engagement with the chamber 56, and the sudden halting thereof by the chamber 58, is effective to break any voids which may exist in the hopper and to promote the free flow of the powder therein into the measuring chamber.

It will be apparent that the precise amount of powder transferred from the chamber 54 into the compacting chamber 56 is variable by adjusting the nuts at the right end of the rods 8 I 62. Thus, the construction shown in Figure 1 provides for Y a device which, by means of a single motor, automatically measures a charge of powder, transfersv the measured charge into a compacting chamber, compacts the same therein while inductively heating the same, and thereafter ejects the briquette and automatically returnsthe press parts to their initial position.

Structural arrangement of the modification of Figure 8 In Figure 8 is shown an arrangement wherein a measuring chamber 8l and a compacting chamber 88 are arranged in abutting relationship in axial alignment. The powdered metal is fed into the chamber 81 from a hopper 80 through a passage 82 which is surrounded by an induction heating coil 83 which latter is suitably insulated by a sleeve B4. 'I'he flow of powder from the hopper 88 into the passage 82 is controlled by a gate 85 which is reciprocable by a hydraulic motor 85. The motor 86 is reciprocated by means of a fourway valve 91 connected thereto. Reciprocably mounted within the measuring .and compacting chambers are a pair of plungers 9i and 92 which are actuated, respectively, by the hydraulic motors 93 and 84. The hydraulic motors 93 and 95 are actuated respectively by hydraulic fluid from the four-way valves 88 and 99.

The compacting chamber 88 is surrounded by the induction coil 89 which is electrically connected with any suitable source of high frequency electrical energy. An insulating sleeve 90 surrounds the chamber 88 and the coil 89 so as to insulate the same electrically and thermally.

Arranged in operatively associated relation with the press proper is a sintering furnace or chamber comprising a conveyor and an inductively heated passage 95 through which the said conveyor passes. The passage 96 is provided with a heat-V ing coil and an insulation sleeve similar to the chamber 88. For the purpose of preventing oxidation or other undesirable chemical changes in the workpiece as it passes through the sintering furnace, the atmosphere thereof may be controlled by a conduit I 08 which may supply any suitable inert gas to the passage 96 so as to blanket the workpiece during its passage through the sintering furnace.

Operation of 'the embodiment of Figure 8 In the operation of the modification shown in Figures 8 and 9, the plungers 9| and 92 are moved into the measuring chamber so as to receive a predetermined charge therebetween. This charge, which has been preheated in the passage 82, may be controlled volumetrically by the manipulation of the gate 85. The plungers 9i and 92, having received the predetermined charge, are moved into the compacting chamber 88 so as to occupy energized so as to heat the said powder to any desired temperature. In this instance the material is preferably only partially sintered, the nal sintering stage taking place within the passage 95 of the sintering oven.

Following the accomplishment of any desired degree of sintering of the workpiece, the plunger 9| Yis withdrawn from the chamber and the plunger 92 is actuated to eject the workpiece. Subsequent to the ejection of the workpiece from the compacting chamber, various machining or shaping operations may be performed thereon before the nal sintering step. Following the accomplishment of Whatever operation it isdesired to perform on the workpiece, it is placed on the conveyor 95 and passed through the passage 96 where it comes under the influence of the heating coil associated with the sintering oven and becomes completely sintered.

It is evident that the energization of the in7 duction coils surrounding the passage 82, -the compacting chamber and the passage 96 may be controlled by switches r rheostats in any man.

ner that is desirable in the operation of the device.

Structural arrangement of the embodiment of Figure The arrangementshown in Figures l0 and'll comprises a horizontally disposed preheating and measuring chamber ||4 which has associated therewith an induction heating coil IIS and a surrounding insulating sleeve II1. Attached to one end of the chamber I I4 is a hopper I I0 which is lled with powdered metal as indicated at III. Reciprocably mounted within the chamber ||4 is a plunger. I I2 which is bored to receive an ejector plunger II3.

The end of the chamber ||4 opposite the hopper ||Il is adapted to be closed by a gate |I5 which is apertured as at |32 to permit the passage therethrough of powdered metal. Adjacent the gate I I5 opposite the chamber I I4 is the compacting chamber I|8 which has reciprocably mounted therein the plunger I I9.

Referring more particularly to Figure l0, it will be seen that the plunger |I2 is connected with a hydraulic motor |22 and that the ejector plunger ||3 is connected with a hydraulic motor |23, the

ejector plunger passing completely through the motor |22. 'Ihe supply of actuating fluid to the motor |22 is controlled by the four-way valve |21 while the valve |28 affords a similar control for the motor I 23. In a similar manner the gate ||5 is actuated by a hydraulic motor |24, the movements -of which are controlled by the fourway valve |29. The plunger ||9 is reciprocated by a motor |26 which is connected to a fluid source through the four-way valve I3 I Attached to the plunger |I9 is a collar |20 which is adapted to engage a reciprocable stop member |2I, the stop member being reciprocated by the motor |25 which is connected through the valve |30 with a fluid source. The stop member |25 is adapted, when moved into the path of the collar |20, to stop the plunger I I9 in its Figure 1l position. When the stop member |23 is withdrawn from the' path of the plunger |20, the

plunger II9 is'free to advance toward the gatev ||5 to compress the material within the compacting or brlquettng chamber.

After the compacting of the material Within the compacting chamber, the plunger IIS is retracted out of the chamber, the gate II5 is actuated to bring the aperture |32 into alignment with the compacting chamber and the ejector plunger ||3 is actuated to remove the briquetted workpiece from the machine. Following the ejection of the workpiece, the plunger |I3 is retracted, the plunger ||9 is moved forwardto its Figure l1 position into engagement with the stop member |2I, and the plunger ||2 is actuated to move a new charge of material into the briquetting chamber. After the actuation of the plunger |I2, the gate ||5 is moved down to its Figure 11 position so as to close off the end of the chamber ||8 and the compacting stroke of the plunger I I9 may now be commenced, Following the closure of the gate ||5, the plunger I I2 is retracted beyond the opening of the hopper |I0 so that a new charge of material falls into the chamber I4. The plunger ||2 is then moved to its Figure 1l position compressing the powder into a compacted mass so that the energization of the coil II6 is effective eiciently to heat the powdered material. It will be evident that the precompressing and heating of the powder Within the chamber I|4 may take place simultaneously with the compacting of the material within the chamber I I8, thus providing for a relatively rapid cycle. Preferably, the material is heated within the, chamber I|4 to sintering temperature and then4 quickly compacted within the chamber I I8 but it is conceivable that the temperature to which the powder is brought within the preheating chamber may be sufficient to cause only partial sintering. In the latter event, a subsequent sintering step would be preformed in order completely to sinter the briquette or workpiece.

In Figure 12 a modified arrangement of the heating coils around the preheating chamber is shown. In this gure the heating chamber is indicated at |40 and the induction coil is wound in steps |4I, |42 and |43 so as to give progressively greater heating elect toward the compacting chamber. In this way the coils may be energized during the period of transfer of the material from the preheating 4chamber to the compacting chamber thereby rapidly to bring the said powder to sintering temperature immediately prior to entering the compacting chamber.

Structural arrangement of the modification of Figure 13 The arrangement shown in Figures 13 and 14 issimilar to the arrangement shown in Figures 8 and l0 but provides for an automatic measuring ldevice of somewhat different design. The compacting chamber indicated at |6| is suitably tted with an induction heating coil and is closed at one end by a member |62 which is attached to a hydraulic motor |14 which reciprocates the said member into and out of engagement with the chamber |6I. trolled by a four-way Valve |11 so as to accomplish thesaid reciprocation of the member |62. Reciprocably mounted in the chamber |6| opposite to the member |62 is a plunger |63, The plunger I 63 is adapted to be reciprocated by the motor |15 which is controlled by the four-way valve |18. The plunger |63 is adapted to compact the material against the member |62 and within the chamber |6|.

Attached to the chamber |6| to the lower side thereof is a preheating chamber |60, fitted with an induction heating coil, and having reciproca- The hydraulic motor is conof equidistantly spaced notches |66 which are adapted to be engaged by a member |61 pivotally mounted at |66 on the chamber |60. 'I'he member |61, has attached thereto an armature |69 oi' a solenoid |10 which is adapted to be energized by a limit switch |1| when the latter is actuated by the cam |12 on the ram |63. The member |61 is urged into engagement with the notches |66 by a spring and is moved out of engagement with the said notches by the armature |69 when the solenoid is energized. 'i

'Ihe chamber |60 is iilled through an opening indicated at |16 in the top of the chamber |6| directly opposite the said chamber. The chamber |60 is filled when' the piston |60 is in its lowermost position and, as the piston moves upwardly the material is displaced in measured quantities' into the compacting chamber |6|.

Operation of the embodiment of Figure 13 In the operation of the embodiment of Figure 13, the piston |60 is retracted to its Figure 14 position bythe motor |16 and the chamber |60 is iilled through the opening |13. The valve |10 is then shifted to actuate the motor |16 to urge the plunger 165 and the piston |60 upwardly, the

upward movement being halted by the engagement of the member '|61 with the uppermost of the notches |60.

Thevalve $11 is then shifted to actuate the motor |10 to move the member |62 into position in the end of the compacting chamber. Assuming that there is a charge of material within the chamber |61, the valve 116 is now shifted to actuate the motor |15 to drive the pressing plunger |63 leftwardly to compact the said charge within the compacting chamber. As with the previous modifications, the induction coil surrounding the compactng chamber may be energized for any predetermined period during the compacting cycle for accomplishing any degree of sinterng desired in the workpiece or briquettc. Following the compacting and sintering. the valve |11 is shifted to actuate the motor |10 to withdraw the member |62 from the end of the compacting chamber, thus allowing the plunger 666 to eject the workpiece. t

Following the ejection of the workpiece, the valve |16 is shifted to retract the plunger |03 to its Figure 13 and 14 position while the Valve |11 may be shifted to return the member |62 to working position; During the retraction stroke of the plunger |63, the cam |12 engages the switch |1i and momentarily closes the same. The momentary closing of the switch |1| energizes the solenoid |10 to actuate the armature |69 thereby withdrawing the member |61 from engagement with the notch |66. The disengagement of the member |61 from the notch |66 is effective to permit the motor |16 to move the plunger |65 and piston |60 upwardly to displace a charge of material from the preheating chamber into the compacting chamber. The solenoid |10 is energized only so long as is necessary to accomplish the disengagement of the member |61 from the notch |66. Therefore, as the next notch |66 approaches the member |61; the latter will be urged into engagement with the notch and the plunger |65 will be halted in a predetermined position thus permitting the piston |64 to displace only a predetermined amount of material into the compacting chamber.

The induction coil associated with the measuring chamber is either continuously or intermittently energized to preheat the material Within the chamber to any desired temperature. This may be accomplished in any desirable and Well known manner similar to those described in connection with the other modifications.

Structural arrangement of the modification of Figure 15 In Figure 15 there is shown an arrangement whereby the measuring of the material is accomplished by weight rather than volumetrically. Referring to Figure 15, there is a chamber 2li having an opening 2|0 through which the material is introduced. Reciprocably mounted within the chamber 2| are the compacting plungers 2 I2 and 2|3 which are actuated, respectively by the fluid operable motors 2|1 and 2|8 which are in turn controlled, respectively by the four-way valves 2|9 and 220.

Arranged around the compacting zone of the chamber 2|0 is an induction coil 2|E and an insulating sleeve 2|6. The induction coil 2|5 is supplied with electrical energy from an oscillation generator of any suitable design.

Referring to the feeding arrangement, this comprises a hopper 200 having a feed passage at 20| which is adapted to be closed by a gate 202. The gate 202 is actuated by an arm 203 which is urged toward gate closing position by a. spring 204. Arranged beneath the hopper 200 is a container 2 06 which is pivotally mounted on a bracket its original position before the charge is com' pletely delivered to the chamber.

The container 205, in its uppermost position, engages the arm 203 thus moving the gate 202 to open position. The downward movement of the container may be halted by a manually operated latch 209 to prevent the premature delivering of a charge of material.

Operation of the embodiment of Figure `15 In considering the operation of the modication of Figure l5, assume that the parts occupy their Figure 15 position wherein the container 20E is delivering a charge of material into the chamber 2|| through the opening 2|0. As soon as the charge of material has poured from the container, the Weight 2061s effective to rotate the arm 201 and container clockwise about their pivotal support. The weight 206 is effective to move the container past the latch 209 and into engagement with the arm 203 thus opening the gate 202. As soon as the gate 202 is opened .powdered material within the hopper 200 pours through the feed passage 20| and into the container 205 until the weight of the material within the container over-balances the weight 206 and moves the said container downwardly out of engagement with the arm 203 thereby permitting the gate 202 to close.A 'Ihe container 205 moves downwardly until stopped by the latch 209, where it remains until the latch is manually actuated.

The charge of material which had been delivered to the chamber 2|0 is compacted between plungers 2|3 and 2|2 by actuating the latter by the motor 2H. The induction coil 2|5 may be energized during the compacting cycle so as more or less completely to sinter the workpiece. Following the accomplishment of the compacting and sintering, the plunger 2|3 is retracted from the compacting chamber and the plunger 2| 2 ejects the workpiece of briquette. Following the ejection the compacting plungers are returned to their Figure position and a new ch'arge may be delivered to the chamber 2|| by actuating the latch 209. v

It will be apparent that the induction coil associated with the feed passage may be energized to provide forany degree of preheating of the material desired. Also, that the particular amount of charge may be predetermined by the adjustment of the weight 206 on the arm 201.

In Figure 17 ls shown an arrangement whereby a charge of material, such as powdered metal, may be thoroughly heated and initimately mixed in a heating chamber from which' it may be forced into a compacting chamber or a die. Inv

this figure a cylinder 250 has reciprocable therein a plunger The cylinder 250 has an enlarged diameter portion at 245 and has arranged therein a spreader or torpedo 246 terminating in an open end adapted to cooperate with a compacting chamber or die opening;

The spreader 246 is fitted with an internal coil as at 244 for the purpose of heating the torpedo or supplying energy to the material which is disposed therearound. The chamber 250 has arranged therearound a coil 24| and an insulating sleeve 240, while the portion 245 has associated therewith the double coil 242, 243.

In operation, a charge of material is placed within the chamber 2,50 ahead of the plunger 25| and is heated by the coil 24|. When th'e plunger is actuated to force the charge 1eftward1y through the chamber, the said charge is forced to pass between the spreader 246 and the enlarger portion 245. In passing throughl this zone, the powdered material is intimatelyy mixed and, since it is restrained to a relatively thin passage, becomes thoroughly and uniformly heated. It will be apparent that the chamber 250 is preferably villed at all times and that the temperature of the mation coil associated with said mold for establishing a field of electromagnetic induction therein when energized, an induction coil associated with said passage. means operable to permit a predetermined amount of material to pass from said hopper into said passage, means for energizing said induction coil associated with said passage so as to heat said predetermined quantity of material, means vfor actuating said pressing plunger so as to permit said heated material to pass into said feed chamber and thereafter to move said material into said mold and to compress the same therein against said removable mold bottom, means foienergizing said induction coil associated with said mold for heating said compacted material to substantially sintering temperature, and means for ejecting said workpiece from said mold.

2. In an apparatus for molding granulated metallic materials, a mold, a member forming a bottom for"'said mold, motor means attached toV said member and selectively operable for retracting said member from said mold, means assoterial be raised to substantially sintering temperature as it passes the spreader 246. Also, it

of structure and arrangement and substitution of equivalents as may come within the scope of th'e appended claims and the invention.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination in an apparatus for compacting materials at least a part of which is metal, a mold, a feed chamber in alignment with said mold, a feed passage communicating with said feed chamber, a hopper communicating with said passage, a pressing plunger reciprocable in said mold and said feed chamber, a second plunger reciprocable in said mold and forming a removable bottom therefor, an inducciated with said mold for inductively heating the material therein, a. feed cylinder connected with said mold, a chamber connected with said feed cylinder for supplying material thereto, means associated with said chamber for inductively heating the material therein, a plunger reciprocable in said chamber for moving said material into said feed cylinder, ratchet means associated with said feed plunger for moving said plunger a predetermined distance during each cycle, a pressing plunger reciprocable' in said feed chamber and said mold for transferring said material from said feed chamber into said mold and for compacting the same in said mold, and means operable automatically for actuating said ratchet mechanism during the retraction stroke of said pressing plunger.

3. In an apparatus for compacting powdered metals, a mold, a feed chamber integral with said mold, a second chamber -opening into said feed chamber for containing powder to be transferred into said' feed chamber, a pressing plunger reciprocable in said feed chamber and said mold, a member adapted to form a mold bottom, a plunger reciprocable in said second chamber, said last mentioned plunger being provided with a plurality of equidistantly spaced notches, a. pivoted member adapted to engage said notches, motor means associated with said last mentioned plunger for continuously urging the same upwardly, motor means associated with said pressing plunger for reciprocating the same, motor means associated with said mold bottom for retracting the same from said mold, means responsive to the retracting movement of 'said pressing plunger for momentarily withdrawing said plvvoted member from said notches, and means for establishing a field of alternating electromagnetic induction in said mold and said second chamber for heating the materials therein.

4. In a press for compacting powdered metals, a compacting chamber, a feed chamber in alignment therewith, a, pair of opposed plungers reciprocable in said feed chamber and said compacting chamber for transferring said powder` from said feed chamber into said compacting Ichamber and for compressing it in the latter, means automatically operable for transferring a predetermined quantity of powder into said feed chamber, and means comprising an induction coil for heating said powder to sintering temperature in said compacting chamber.

l 5. In a press for compacting powdered or granulated metals a compacting chamber, a feed chamber in axial alignment with said compacting chamber, a supply means connected with said feed chamber for supplying said metal thereto, a pair of opposed pressing plungers reciprocable in said chambers, motor means selectively operable for causing said plungers to transfer material from said feed-chamber to said compacting chamber and for compacting it in the latter, means for retracting one of said plungers from said compacting chamber While advancing the other of said plungers for ejecting the compacted workpiece, means automatically operable in response tothe reciprocation of one of said plungers for supplying a measured quantity of said metal to said feed chamber, and means comprising induction coils for preheating said metal prior to its entrance into said feed chamber and also for heating it within said compacting chamber.

6. In a press for compactingpowdered metals into substantially solid workpieceaa feed chamber foi` receiving a quantity of said powder, means for creating an alternating field of electro-magnetic induction within the powder supplied to said chamber for preheating the same, a die cavity within which said preheated powder is to be compacted, means for creating an alternating field of electro-magnetic induction in the powder in said cavity for heating the same to sintering temperature, and opposed pressing members operable during one and the same stroke to transfer the preheated material from said feed chamber into said die cavity and for compacting it therein.-

7. In a press for compacting granulated materials, a feed chamber for receiving said material, means adjustable for determining the quantity of material supplied to said chamber, a compacting chamber, means comprising induction coils for heating the material supplied to said feed chamber and also the material in said compacting chamber, and means comprising opposed pressing plungers and actuating motors therefor for transferring the material from said feed chamber to said compacting chamber and for compacting it therein and for electing the workpiece therefrom.

8. In a press for compacting granulated materials, a mold for receiving a predetermined quantity of said material, a pair of plungers mounted for reciprocation in said mold and operable to compact said material therebetween, an induction ccil wound around said mold and operable when energized to heat the material within said mold by electro-magnetic induction, a material containing means in which one of said plungers is reciprocable. an induction coil wound l around said containing means and operable when energized to heat'the material therein, means for actuating said one plunger to transfer material from said containing means to said mold, means for effecting relative movement between said plungers to compact said material within said mold, means for retracting one of said plungers from said mold to permit the election therefrom of said compacted material and means for actuating the other of said plungers to accomplish said ejection.

9. In a press for compacting powdered metals. a. compacting chamber, a feed chamber, a pair of opposed plungers reciprocable in said compacting chamber for compecting material therein and at least one thereof reciprocable in said feed chamber for transferring powder into said com pacting chamber, means for supplying material to said feed chamber and means adjustable for determining the exact quantity of said supply of material, and means comprising an induction coil for heating said material in said compacting chamber.

l0. In a press for compacting powdered metals, a compacting chamber, a feed chamber, a pair of opposed plungers reciprocable in said compacting chamber for compacting material therein -and at least one thereof reciprocable in said feed chamber for transferring powder into said compacting chamber, means for supplying material to said feed chamber and means adjustable for determining the exact quantity of said supply of material, and means comprising induction coils for heating said material before and after the delivery thereof to said compacting chamber.

11. In a press for compacting powdered or granulated material, a mold, a chamber arranged in axial alignment with said mold, a hopper connected with said chamber for supplying said material thereto, a pair of plungers reciprocable in said mold and at least one thereof being reciprocable in said chamber, means for positioning said plungers a predetermined position apart within said chamber so as to receive a predetermined charge of material therebetween from said hopper, means for moving said plungers in unison from said chamber into said mold, means for halting one of said plungers while continuing the movement Vof the other so as to compact said material between said plungers, means for retracting said last mentioned plunger together with said chamber from said mold, means operable for actuating the other of said plungers for ejecting said compact, and means comprising induction coils for heating the Imaterial before it is delivered to said mold and also for heating said compact within said mold by electro-magnetic induction.

12. In an apparatus for compacting divided materials at least a portion of which is metal, a l

compacting chamber, a feed chamber, a. passage connecting said chambers, a pair of opposed pressing members reciprocable in said compacting chamber for compacting material therein and at least one thereof reciprocable in said feed chamber and said passage for transferring material to said compacting chamber, motor means selectively operable for actuating said plungers, means operable automatically to supply weighed charges of material to said feed chamber, and means comprising an induction coil for heating the material within said compacting chamber by electro-magnetic induction.

13. In an apparatus for compacting divided materials at least a portion of which is metal, a compacting chamber, a feed chamber, a passage connecting said chambers, a pair of opposed pressing members reciprocable in said compacting chamber for compacting material therein and at least one thereof reciprocable in said feed chamber and said passage for transferring ma.- terial to said compacting chamber, motor means selectively operable for actuating said plungers, means operable automatically to supply weighed charges of material to said feed chamber, and means comprising induction coils for preheating the material prior to the weighing thereof and also for heating the material in the compacting chamber.

HARRY A. TOUI-m, Jl. 

